1. Field of the Invention
The present invention relates to a power transmission apparatus of clothes washing machines.
2. Description of the Prior Art
The conventional art will be described with reference to the attached drawings. A conventional washing machine, as illustrated in FIGS. 1, 2 and 3, includes a housing 1, water supply means 8 disposed at the back of the housing 1 for supplying water to a washing/spin-dry tub 6 and drain means 9 disposed beneath the washing/spin-dry tub 6 for draining the water in the wash/spin-dry tub 6 out of the washing machine.
The water supply means 8 is arranged thereunder with detergent dissolving means 10 for dissolving detergent in the water to supply into an outer tub 2 and the wash/spin-dry tub 6. The housing 1 is installed therein with the outer tub 2, and the wash/spin-dry tub 6 is provided therein.
Agitating member 7 is disposed on the floor of the wash/spin-dry tub 6 so as to agitate and wash laundry by applying physical force thereto, simultaneously rotating right and left on receipt of power from power transmission means to make the water turbulent.
The out tub 2 is centrally mounted with a washing shaft 11 connected to the agitating member 7 and a spin dry shaft 12 connected to the washing/spin-dry tub 6, and a bearing 13a is releasably and rotatably disposed between the washing shaft 11 and the spin-dry shaft 12.
Furthermore, the outer tub 2 is provided at a bottom surface thereof with power generating means 3 for generating power to rotate the washing shaft 11 and the spin-dry shaft 12, decelerating means 4 disposed underneath the power generating means 3 to decelerate a rotary speed transmitted from the power generating means 3 and power switching means 5 for cutting off the power transmitted to the spin-dry shaft 12 during washing and for connecting the power transmitted to the spin-dry shaft 12 during spin-dry process.
Here, the power generating means 3 consists of a stator 31a, a rotor 31b, a motor 31, a motor shaft 32, and upper and lower housing 33 and 34 for covering the motor 31 and the motor shaft 32. The motor shaft 32 includes a ball bearing 14 disposed between a lower inner circumference thereof and an external peripheral surface of the spin-dry shaft 12 and a metal bearing 13b mounted between a lower inner circumference thereof and an external peripheral surface of the washing shaft 11, thereby preventing transfer of rotation at the motor shaft 32. The motor shaft 32 is meshed into a planetary gear 42 in order to transfer turning effect to a plurality of planetary gears 42.
The decelerating means 4 is arranged with an internal gear 41 formed with teeth at an inner circumference thereof, a plurality of planetary gears 42 disposed at an inner circumference thereof to be meshed into the internal gear 41 and to rotate, an upper carrier 23 and a lower carrier 24 respectively disposed above and underneath the plurality gears 42 so as to connect a central shaft 42a of the planetary gears 42 and to allow the planetary gears 42 to rotate, and a cover 45 for covering external bottoms of each part.
Here, the lower carrier 44 is centrally coupled to a lower end of the washing shaft 11 by a serration method so as to be cooperatively rotated with the washing shaft 11. The power switching means 5 includes a cam lever 51 rotatably coupled to one side of the upper and lower housings 33 and 34 at the power generating means 3 and having a cam 51a thereon, a clutch lever 52 seesawing around a hinge 52a according to rotation of the cam 51a, a lower clutch 54 integrally coupled to an upper surface of the motor shaft 32, an upper clutch 53 connected at one end thereof to the clutch lever 52 and coupled to a periphery of the spin-dry shaft 12 by serration method for vertical movement and interrupting the power by a meshed operation with the lower clutch 54, a gear lever 55 coupled at a right angle to a lower side of the cam lever 51 to cooperatively rotate according to rotation of the cam lever 51, a first cam 56 meshed to one side of the gear lever 55 to cooperatively rotate and formed at an inner circumference thereof with a guide unit, a second cam 57 formed with a slant guide groove into which the guide unit of the first cam 56 is inserted so as to be vertically moved according to the rotation of the first cam 56, and coil springs 58 and 59 respectively disposed at inner circumferences of the second cam 57 and the lower clutch 54 so as to be compressed and elongated during switch from washing stroke to spin-dry stroke. The internal gear 41 is formed at an upper surface thereof with an insertion groove 41a into which one side of the second cam 57 is inserted so as to restrain the rotation of the internal gear 41 by way of downward insertion of the second cam 57 during the washing stroke.
In the washing machine thus constructed, when a desired washing condition is selected and a power is applied during washing process, an adequate amount of water is supplied into the wash/spin-dry tub 6, and when the supply of the water is completed, the motor 31 centrally disposed underneath the outer tub 2 begins to operate.
Successively, as illustrated in FIG. 2, the motor shaft 32 is rotated at a high speed according to operation of the motor 31 and the plurality of planetary gears 42 meshed into the lower end of the motor shaft 32 are rotated.
The lower carrier 44 connected to the central shaft 42a of the planetary gears 42 is then rotated to thereby rotate the washing shaft 11 centrally connected to the lower carrier 44 by the serration method.
At this time, the first cam 56 meshed into the gear lever 55 which cooperatively rotates underneath the cam lever 51 by way of the gear lever 55 is rotated at a predetermined circle, and successively, the guide unit of the first cam 56 moves along the guide groove at the second cam 57. At the same time, the second cam 57 is moved downward according to sliding contact with the guide unit of the first cam 51 by resilient force of the coil spring 58 compressed at an inner side of the second cam 57. By this, one side of the second cam 57 is inserted into the insertion groove 41a of the internal gear 41 to thereby restrain rotation of the internal gear 41.
Successively, the washing shaft 11 is rotated at a reduced speed according to the planetary gears 42 and the lower carrier 44 which have been reduced in speed thereof because the internal gear 41 is fixed and is not rotated by the restraint of the second cam 57. The agitating member 7 connected to the washing shaft 11 is then rotated reversibly left and right to perform the washing.
Meanwhile, along with the washing operation thus described, the cam 5la is rotated by activation of the cam lever 51 to cause the clutch lever 52 to seesaw around the hinge 52a, and successively, the upper clutch 53 connected to one side of the clutch lever 52 is upwardly moved to thereby release the meshed coupling with the lower clutch 54 and to prevent the power of the motor 31 from being transferred to the spin-dry shaft 12.
After the washing thus described is executed, and a predetermined time lapses to complete the washing, the water is drained out, rinsings are performed several times and spin-dry stroke is started. When the spin-dry stroke is started, as illustrated in FIG. 3, the cam 51a is rotated by activation of the cam lever 51 and the clutch lever 52 seesaws around the hinge 52a to thereby move downward the upper clutch 53 connected to one side of the clutch lever 54. Successively, the spin-dry shaft 12 coupled by the serration method to the inner circumference of the upper clutch 53 can receive rotation of the rotor shaft 32.
When the motor shaft 32 is rotated at a high speed, so does the spin-dry shaft 12, such that the wash/spin-dry tub 6 connected to the spin-dry shaft 12 is also rotated at a high speed to perform the spin-dry.
Meanwhile, when the motor 31 is activated to rotate the motor shaft 32 at a high speed, the plurality of planetary gears 42 meshed into a bottom end of the motor shaft 32 are rotated. At this time, the first cam 56 meshed into the gear lever 55 which is cooperatively rotated under the cam lever 51 rotates at a predetermined radius, by which the guide unit of the first cam 56 moves along the guide groove of the second cam 57. The coil springs 58 is then compressed by the second cam 57, where the second cam 57 slidingly contacts the guide unit of the first cam 51 to move upward. The second cam 57 is detached from the insertion groove 41a at the internal gear 41 to release the fixation of the internal gear 41. The internal gear 41 is rotated together according to the rotation of the plurality gears 42.
Subsequently, because the internal gear 41 is rotated with fixation thereof being released, the washing shaft 11 is not reduced in speed by the planetary gears 42 and lower carrier 44 to cause the decelerating means 4 to race. According to the racing of the decelerating means 4, the washing shaft 11 is rotated for a predetermined time to thereafter stop rotating and the spin-dry shaft 12 having received the power from the motor 31 is rotated. The wash/spin-dry tub 6 connected thereto is rotated at a high speed to perform the spin-dry.